Field of the Invention
The present invention relates to an electronic apparatus including a first printed-circuit board, a second printed-circuit board, and a cable connected to the first and second printed-circuit, boards.
Description of the Related Art
In recent years, flexible flat cables (FFCs) have been frequently used for connecting a plurality of printed-circuit boards included in electronic apparatuses because of low cost. Furthermore, as the apparatuses become multifunctional and faster, the number of data transmission lines and the number of control signal lines increase, whereas the demand is increasing for reductions in the sizes of the apparatuses. Thus, while the number of conductors in FFCs also increases, some FFCs in which a space between pins is narrow are employed to achieve space-saving wiring.
In cases where relatively less power is consumed in a printed-circuit board, which is a connection destination, some FFCs are used for supplying power in addition to data signals and control signals.
In such a case, typically, to reduce impedance and noise in a conductor that supplies power, a conductor connected to ground is sometimes provided adjacent to the conductor that supplies power. The conductor connected to ground is connected to a terminal connected to ground in a printed-circuit board to which an FFC is connected.
An FFC includes evenly spaced thin-film conductors that are sandwiched between thin insulators. The FFC is inserted into a slit opening of a connector provided on a printed-circuit board and thus is connected to the connector. At this time, the FFC may be inserted into the connector at an angle. In this case, in the case where a conductor adjacent to a conductor that supplies power is connected to ground, a short circuit may occur between a power supply and ground and, as a result, cause a malfunction in an apparatus.
Japanese Patent Laid-Open No. 2012-170738 discloses, as illustrated in FIG. 5, a connector 72 which includes a plurality of terminals 75a to 75j including power supply terminals and a ground terminal, and a connector connection portion 84 which is formed at an end of an FFC 71 and in which inner conductors 82a to 82j whose coverings have been stripped are exposed. The connector connection portion 84 of the FFC 71 is inserted into the connector 72 and thus the FFC 71 is connected to the connector 72. Among the plurality of terminals 75a to 75j, terminals 75e, 75g, and 75i respectively disposed adjacent to power supply terminals 75f and 75h and a ground terminal 75j serve as idle terminals. In the connector connection portion 84, conductors 82e, 82g, and 82i corresponding to these idle terminals remain covered, and conductors corresponding to the other terminals are exposed. In the case of the FFC 71 illustrated in FIG. 5, a process of causing the conductors of the FFC 71 corresponding to the idle terminals to remain covered has to be performed, thereby causing an increase in cost.